mx6/626 trans. problem
 

Hello,I have a 1989 Mazda mx6 and the automatic transmission wont go into gear.I can go up and down with the lever but it doesnt go into gear.I checked the fluid and it is fine.The hold light on the dash blinks on and off and when I put it in drive or reverse,it seems to want to go into gear beacause the engine changes rpm.Is there a way to diagnose the problem other than to take it to a mechanic?I'd appreciate any help.Thanks.